The leakage would happend when create_namespace_pmem() meets an invalid
label which gets failure in validating isetcookie.
Try to resuse the devs that may have already been allocated with size
(2 * sizeof(dev)) previously.
A kmemleak reports:
unreferenced object 0xffff88800dda1980 (size 16):
comm "kworker/u10:5", pid 69, jiffies 4294671781
hex dump (first 16 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 0):
[<00000000c5dea560>] __kmalloc+0x32c/0x470
[<000000009ed43c83>] nd_region_register_namespaces+0x6fb/0x1120 [libnvdimm]
[<000000000e07a65c>] nd_region_probe+0xfe/0x210 [libnvdimm]
[<000000007b79ce5f>] nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm]
[<00000000a5f3da2e>] really_probe+0xc6/0x390
[<00000000129e2a69>] __driver_probe_device+0x78/0x150
[<000000002dfed28b>] driver_probe_device+0x1e/0x90
[<00000000e7048de2>] __device_attach_driver+0x85/0x110
[<0000000032dca295>] bus_for_each_drv+0x85/0xe0
[<00000000391c5a7d>] __device_attach+0xbe/0x1e0
[<0000000026dabec0>] bus_probe_device+0x94/0xb0
[<00000000c590d936>] device_add+0x656/0x870
[<000000003d69bfaa>] nd_async_device_register+0xe/0x50 [libnvdimm]
[<000000003f4c52a4>] async_run_entry_fn+0x2e/0x110
[<00000000e201f4b0>] process_one_work+0x1ee/0x600
[<000000006d90d5a9>] worker_thread+0x183/0x350
Cc: Dave Jiang <dave.ji...@intel.com>
Cc: Ira Weiny <ira.we...@intel.com>
Fixes: 1b40e09a1232 ("libnvdimm: blk labels and namespace instantiation")
Signed-off-by: Li Zhijian <lizhij...@fujitsu.com>
---
Cc: Ira Weiny <ira.we...@intel.com>
> From what I can tell create_namespace_pmem() must be returning EAGAIN
> which leaves devs allocated but fails to increment count. Thus there are
> no valid labels but devs was not free'ed.
> Can you trace the error you are seeing a bit more to see if this is the
> case?
Hi Ira, Sorry for the late reply. I have reproduced it these days.
Yeah, the LSA is containing a label in which the isetcookie is invalid.
V2:
update description and comment
---
drivers/nvdimm/namespace_devs.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index d6d558f94d6b..28c9afc01dca 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1994,7 +1994,13 @@ static struct device **scan_labels(struct nd_region
*nd_region)
/* Publish a zero-sized namespace for userspace to configure. */
nd_mapping_free_labels(nd_mapping);
- devs = kcalloc(2, sizeof(dev), GFP_KERNEL);
+ /*
+ * Try to use the devs that may have already been allocated
+ * above first. This would happend when create_namespace_pmem()
+ * meets an invalid label.
+ */
+ if (!devs)
+ devs = kcalloc(2, sizeof(dev), GFP_KERNEL);
if (!devs)
goto err;
--
2.29.2
